crypto: arm64/crc32 - accelerated support based on x86 SSE implementation

This is a combination of the the Intel algorithm implemented using SSE
and PCLMULQDQ instructions from arch/x86/crypto/crc32-pclmul_asm.S, and
the new CRC32 extensions introduced for both 32-bit and 64-bit ARM in
version 8 of the architecture. Two versions of the above combo are
provided, one for CRC32 and one for CRC32C.

The PMULL/NEON algorithm is faster, but operates on blocks of at least
64 bytes, and on multiples of 16 bytes only. For the remaining input,
or for all input on systems that lack the PMULL 64x64->128 instructions,
the CRC32 instructions will be used.

Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

arch/arm64/crypto/Kconfig

@@ -36,6 +36,11 @@ config CRYPTO_CRCT10DIF_ARM64_CE
 	depends on KERNEL_MODE_NEON && CRC_T10DIF
 	select CRYPTO_HASH
 
+config CRYPTO_CRC32_ARM64_CE
+	tristate "CRC32 and CRC32C digest algorithms using PMULL instructions"
+	depends on KERNEL_MODE_NEON && CRC32
+	select CRYPTO_HASH
+
 config CRYPTO_AES_ARM64_CE
 	tristate "AES core cipher using ARMv8 Crypto Extensions"
 	depends on ARM64 && KERNEL_MODE_NEON
@@ -66,4 +71,5 @@ config CRYPTO_CRC32_ARM64
 	tristate "CRC32 and CRC32C using optional ARMv8 instructions"
 	depends on ARM64
 	select CRYPTO_HASH
+
 endif

arch/arm64/crypto/Makefile

@@ -20,6 +20,9 @@ ghash-ce-y := ghash-ce-glue.o ghash-ce-core.o
 obj-$(CONFIG_CRYPTO_CRCT10DIF_ARM64_CE) += crct10dif-ce.o
 crct10dif-ce-y := crct10dif-ce-core.o crct10dif-ce-glue.o
 
+obj-$(CONFIG_CRYPTO_CRC32_ARM64_CE) += crc32-ce.o
+crc32-ce-y:= crc32-ce-core.o crc32-ce-glue.o
+
 obj-$(CONFIG_CRYPTO_AES_ARM64_CE) += aes-ce-cipher.o
 CFLAGS_aes-ce-cipher.o += -march=armv8-a+crypto
 

arch/arm64/crypto/crc32-ce-core.S

@@ -0,0 +1,266 @@
+/*
+ * Accelerated CRC32(C) using arm64 CRC, NEON and Crypto Extensions instructions
+ *
+ * Copyright (C) 2016 Linaro Ltd <ard.biesheuvel@linaro.org>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+/* GPL HEADER START
+ *
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 only,
+ * as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * General Public License version 2 for more details (a copy is included
+ * in the LICENSE file that accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License
+ * version 2 along with this program; If not, see http://www.gnu.org/licenses
+ *
+ * Please  visit http://www.xyratex.com/contact if you need additional
+ * information or have any questions.
+ *
+ * GPL HEADER END
+ */
+
+/*
+ * Copyright 2012 Xyratex Technology Limited
+ *
+ * Using hardware provided PCLMULQDQ instruction to accelerate the CRC32
+ * calculation.
+ * CRC32 polynomial:0x04c11db7(BE)/0xEDB88320(LE)
+ * PCLMULQDQ is a new instruction in Intel SSE4.2, the reference can be found
+ * at:
+ * http://www.intel.com/products/processor/manuals/
+ * Intel(R) 64 and IA-32 Architectures Software Developer's Manual
+ * Volume 2B: Instruction Set Reference, N-Z
+ *
+ * Authors:   Gregory Prestas <Gregory_Prestas@us.xyratex.com>
+ *	      Alexander Boyko <Alexander_Boyko@xyratex.com>
+ */
+
+#include <linux/linkage.h>
+#include <asm/assembler.h>
+
+	.text
+	.align		6
+	.cpu		generic+crypto+crc
+
+.Lcrc32_constants:
+	/*
+	 * [x4*128+32 mod P(x) << 32)]'  << 1   = 0x154442bd4
+	 * #define CONSTANT_R1  0x154442bd4LL
+	 *
+	 * [(x4*128-32 mod P(x) << 32)]' << 1   = 0x1c6e41596
+	 * #define CONSTANT_R2  0x1c6e41596LL
+	 */
+	.octa		0x00000001c6e415960000000154442bd4
+
+	/*
+	 * [(x128+32 mod P(x) << 32)]'   << 1   = 0x1751997d0
+	 * #define CONSTANT_R3  0x1751997d0LL
+	 *
+	 * [(x128-32 mod P(x) << 32)]'   << 1   = 0x0ccaa009e
+	 * #define CONSTANT_R4  0x0ccaa009eLL
+	 */
+	.octa		0x00000000ccaa009e00000001751997d0
+
+	/*
+	 * [(x64 mod P(x) << 32)]'       << 1   = 0x163cd6124
+	 * #define CONSTANT_R5  0x163cd6124LL
+	 */
+	.quad		0x0000000163cd6124
+	.quad		0x00000000FFFFFFFF
+
+	/*
+	 * #define CRCPOLY_TRUE_LE_FULL 0x1DB710641LL
+	 *
+	 * Barrett Reduction constant (u64`) = u` = (x**64 / P(x))`
+	 *                                                      = 0x1F7011641LL
+	 * #define CONSTANT_RU  0x1F7011641LL
+	 */
+	.octa		0x00000001F701164100000001DB710641
+
+.Lcrc32c_constants:
+	.octa		0x000000009e4addf800000000740eef02
+	.octa		0x000000014cd00bd600000000f20c0dfe
+	.quad		0x00000000dd45aab8
+	.quad		0x00000000FFFFFFFF
+	.octa		0x00000000dea713f10000000105ec76f0
+
+	vCONSTANT	.req	v0
+	dCONSTANT	.req	d0
+	qCONSTANT	.req	q0
+
+	BUF		.req	x0
+	LEN		.req	x1
+	CRC		.req	x2
+
+	vzr		.req	v9
+
+	/**
+	 * Calculate crc32
+	 * BUF - buffer
+	 * LEN - sizeof buffer (multiple of 16 bytes), LEN should be > 63
+	 * CRC - initial crc32
+	 * return %eax crc32
+	 * uint crc32_pmull_le(unsigned char const *buffer,
+	 *                     size_t len, uint crc32)
+	 */
+ENTRY(crc32_pmull_le)
+	adr		x3, .Lcrc32_constants
+	b		0f
+
+ENTRY(crc32c_pmull_le)
+	adr		x3, .Lcrc32c_constants
+
+0:	bic		LEN, LEN, #15
+	ld1		{v1.16b-v4.16b}, [BUF], #0x40
+	movi		vzr.16b, #0
+	fmov		dCONSTANT, CRC
+	eor		v1.16b, v1.16b, vCONSTANT.16b
+	sub		LEN, LEN, #0x40
+	cmp		LEN, #0x40
+	b.lt		less_64
+
+	ldr		qCONSTANT, [x3]
+
+loop_64:		/* 64 bytes Full cache line folding */
+	sub		LEN, LEN, #0x40
+
+	pmull2		v5.1q, v1.2d, vCONSTANT.2d
+	pmull2		v6.1q, v2.2d, vCONSTANT.2d
+	pmull2		v7.1q, v3.2d, vCONSTANT.2d
+	pmull2		v8.1q, v4.2d, vCONSTANT.2d
+
+	pmull		v1.1q, v1.1d, vCONSTANT.1d
+	pmull		v2.1q, v2.1d, vCONSTANT.1d
+	pmull		v3.1q, v3.1d, vCONSTANT.1d
+	pmull		v4.1q, v4.1d, vCONSTANT.1d
+
+	eor		v1.16b, v1.16b, v5.16b
+	ld1		{v5.16b}, [BUF], #0x10
+	eor		v2.16b, v2.16b, v6.16b
+	ld1		{v6.16b}, [BUF], #0x10
+	eor		v3.16b, v3.16b, v7.16b
+	ld1		{v7.16b}, [BUF], #0x10
+	eor		v4.16b, v4.16b, v8.16b
+	ld1		{v8.16b}, [BUF], #0x10
+
+	eor		v1.16b, v1.16b, v5.16b
+	eor		v2.16b, v2.16b, v6.16b
+	eor		v3.16b, v3.16b, v7.16b
+	eor		v4.16b, v4.16b, v8.16b
+
+	cmp		LEN, #0x40
+	b.ge		loop_64
+
+less_64:		/* Folding cache line into 128bit */
+	ldr		qCONSTANT, [x3, #16]
+
+	pmull2		v5.1q, v1.2d, vCONSTANT.2d
+	pmull		v1.1q, v1.1d, vCONSTANT.1d
+	eor		v1.16b, v1.16b, v5.16b
+	eor		v1.16b, v1.16b, v2.16b
+
+	pmull2		v5.1q, v1.2d, vCONSTANT.2d
+	pmull		v1.1q, v1.1d, vCONSTANT.1d
+	eor		v1.16b, v1.16b, v5.16b
+	eor		v1.16b, v1.16b, v3.16b
+
+	pmull2		v5.1q, v1.2d, vCONSTANT.2d
+	pmull		v1.1q, v1.1d, vCONSTANT.1d
+	eor		v1.16b, v1.16b, v5.16b
+	eor		v1.16b, v1.16b, v4.16b
+
+	cbz		LEN, fold_64
+
+loop_16:		/* Folding rest buffer into 128bit */
+	subs		LEN, LEN, #0x10
+
+	ld1		{v2.16b}, [BUF], #0x10
+	pmull2		v5.1q, v1.2d, vCONSTANT.2d
+	pmull		v1.1q, v1.1d, vCONSTANT.1d
+	eor		v1.16b, v1.16b, v5.16b
+	eor		v1.16b, v1.16b, v2.16b
+
+	b.ne		loop_16
+
+fold_64:
+	/* perform the last 64 bit fold, also adds 32 zeroes
+	 * to the input stream */
+	ext		v2.16b, v1.16b, v1.16b, #8
+	pmull2		v2.1q, v2.2d, vCONSTANT.2d
+	ext		v1.16b, v1.16b, vzr.16b, #8
+	eor		v1.16b, v1.16b, v2.16b
+
+	/* final 32-bit fold */
+	ldr		dCONSTANT, [x3, #32]
+	ldr		d3, [x3, #40]
+
+	ext		v2.16b, v1.16b, vzr.16b, #4
+	and		v1.16b, v1.16b, v3.16b
+	pmull		v1.1q, v1.1d, vCONSTANT.1d
+	eor		v1.16b, v1.16b, v2.16b
+
+	/* Finish up with the bit-reversed barrett reduction 64 ==> 32 bits */
+	ldr		qCONSTANT, [x3, #48]
+
+	and		v2.16b, v1.16b, v3.16b
+	ext		v2.16b, vzr.16b, v2.16b, #8
+	pmull2		v2.1q, v2.2d, vCONSTANT.2d
+	and		v2.16b, v2.16b, v3.16b
+	pmull		v2.1q, v2.1d, vCONSTANT.1d
+	eor		v1.16b, v1.16b, v2.16b
+	mov		w0, v1.s[1]
+
+	ret
+ENDPROC(crc32_pmull_le)
+ENDPROC(crc32c_pmull_le)
+
+	.macro		__crc32, c
+0:	subs		x2, x2, #16
+	b.mi		8f
+	ldp		x3, x4, [x1], #16
+CPU_BE(	rev		x3, x3		)
+CPU_BE(	rev		x4, x4		)
+	crc32\c\()x	w0, w0, x3
+	crc32\c\()x	w0, w0, x4
+	b.ne		0b
+	ret
+
+8:	tbz		x2, #3, 4f
+	ldr		x3, [x1], #8
+CPU_BE(	rev		x3, x3		)
+	crc32\c\()x	w0, w0, x3
+4:	tbz		x2, #2, 2f
+	ldr		w3, [x1], #4
+CPU_BE(	rev		w3, w3		)
+	crc32\c\()w	w0, w0, w3
+2:	tbz		x2, #1, 1f
+	ldrh		w3, [x1], #2
+CPU_BE(	rev16		w3, w3		)
+	crc32\c\()h	w0, w0, w3
+1:	tbz		x2, #0, 0f
+	ldrb		w3, [x1]
+	crc32\c\()b	w0, w0, w3
+0:	ret
+	.endm
+
+	.align		5
+ENTRY(crc32_armv8_le)
+	__crc32
+ENDPROC(crc32_armv8_le)
+
+	.align		5
+ENTRY(crc32c_armv8_le)
+	__crc32		c
+ENDPROC(crc32c_armv8_le)

arch/arm64/crypto/crc32-ce-glue.c

@@ -0,0 +1,212 @@
+/*
+ * Accelerated CRC32(C) using arm64 NEON and Crypto Extensions instructions
+ *
+ * Copyright (C) 2016 Linaro Ltd <ard.biesheuvel@linaro.org>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+#include <linux/cpufeature.h>
+#include <linux/crc32.h>
+#include <linux/init.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/string.h>
+
+#include <crypto/internal/hash.h>
+
+#include <asm/hwcap.h>
+#include <asm/neon.h>
+#include <asm/unaligned.h>
+
+#define PMULL_MIN_LEN		64L	/* minimum size of buffer
+					 * for crc32_pmull_le_16 */
+#define SCALE_F			16L	/* size of NEON register */
+
+asmlinkage u32 crc32_pmull_le(const u8 buf[], u64 len, u32 init_crc);
+asmlinkage u32 crc32_armv8_le(u32 init_crc, const u8 buf[], size_t len);
+
+asmlinkage u32 crc32c_pmull_le(const u8 buf[], u64 len, u32 init_crc);
+asmlinkage u32 crc32c_armv8_le(u32 init_crc, const u8 buf[], size_t len);
+
+static u32 (*fallback_crc32)(u32 init_crc, const u8 buf[], size_t len);
+static u32 (*fallback_crc32c)(u32 init_crc, const u8 buf[], size_t len);
+
+static int crc32_pmull_cra_init(struct crypto_tfm *tfm)
+{
+	u32 *key = crypto_tfm_ctx(tfm);
+
+	*key = 0;
+	return 0;
+}
+
+static int crc32c_pmull_cra_init(struct crypto_tfm *tfm)
+{
+	u32 *key = crypto_tfm_ctx(tfm);
+
+	*key = ~0;
+	return 0;
+}
+
+static int crc32_pmull_setkey(struct crypto_shash *hash, const u8 *key,
+			      unsigned int keylen)
+{
+	u32 *mctx = crypto_shash_ctx(hash);
+
+	if (keylen != sizeof(u32)) {
+		crypto_shash_set_flags(hash, CRYPTO_TFM_RES_BAD_KEY_LEN);
+		return -EINVAL;
+	}
+	*mctx = le32_to_cpup((__le32 *)key);
+	return 0;
+}
+
+static int crc32_pmull_init(struct shash_desc *desc)
+{
+	u32 *mctx = crypto_shash_ctx(desc->tfm);
+	u32 *crc = shash_desc_ctx(desc);
+
+	*crc = *mctx;
+	return 0;
+}
+
+static int crc32_pmull_update(struct shash_desc *desc, const u8 *data,
+			 unsigned int length)
+{
+	u32 *crc = shash_desc_ctx(desc);
+	unsigned int l;
+
+	if ((u64)data % SCALE_F) {
+		l = min_t(u32, length, SCALE_F - ((u64)data % SCALE_F));
+
+		*crc = fallback_crc32(*crc, data, l);
+
+		data += l;
+		length -= l;
+	}
+
+	if (length >= PMULL_MIN_LEN) {
+		l = round_down(length, SCALE_F);
+
+		kernel_neon_begin_partial(10);
+		*crc = crc32_pmull_le(data, l, *crc);
+		kernel_neon_end();
+
+		data += l;
+		length -= l;
+	}
+
+	if (length > 0)
+		*crc = fallback_crc32(*crc, data, length);
+
+	return 0;
+}
+
+static int crc32c_pmull_update(struct shash_desc *desc, const u8 *data,
+			 unsigned int length)
+{
+	u32 *crc = shash_desc_ctx(desc);
+	unsigned int l;
+
+	if ((u64)data % SCALE_F) {
+		l = min_t(u32, length, SCALE_F - ((u64)data % SCALE_F));
+
+		*crc = fallback_crc32c(*crc, data, l);
+
+		data += l;
+		length -= l;
+	}
+
+	if (length >= PMULL_MIN_LEN) {
+		l = round_down(length, SCALE_F);
+
+		kernel_neon_begin_partial(10);
+		*crc = crc32c_pmull_le(data, l, *crc);
+		kernel_neon_end();
+
+		data += l;
+		length -= l;
+	}
+
+	if (length > 0) {
+		*crc = fallback_crc32c(*crc, data, length);
+	}
+
+	return 0;
+}
+
+static int crc32_pmull_final(struct shash_desc *desc, u8 *out)
+{
+	u32 *crc = shash_desc_ctx(desc);
+
+	put_unaligned_le32(*crc, out);
+	return 0;
+}
+
+static int crc32c_pmull_final(struct shash_desc *desc, u8 *out)
+{
+	u32 *crc = shash_desc_ctx(desc);
+
+	put_unaligned_le32(~*crc, out);
+	return 0;
+}
+
+static struct shash_alg crc32_pmull_algs[] = { {
+	.setkey			= crc32_pmull_setkey,
+	.init			= crc32_pmull_init,
+	.update			= crc32_pmull_update,
+	.final			= crc32_pmull_final,
+	.descsize		= sizeof(u32),
+	.digestsize		= sizeof(u32),
+
+	.base.cra_ctxsize	= sizeof(u32),
+	.base.cra_init		= crc32_pmull_cra_init,
+	.base.cra_name		= "crc32",
+	.base.cra_driver_name	= "crc32-arm64-ce",
+	.base.cra_priority	= 200,
+	.base.cra_blocksize	= 1,
+	.base.cra_module	= THIS_MODULE,
+}, {
+	.setkey			= crc32_pmull_setkey,
+	.init			= crc32_pmull_init,
+	.update			= crc32c_pmull_update,
+	.final			= crc32c_pmull_final,
+	.descsize		= sizeof(u32),
+	.digestsize		= sizeof(u32),
+
+	.base.cra_ctxsize	= sizeof(u32),
+	.base.cra_init		= crc32c_pmull_cra_init,
+	.base.cra_name		= "crc32c",
+	.base.cra_driver_name	= "crc32c-arm64-ce",
+	.base.cra_priority	= 200,
+	.base.cra_blocksize	= 1,
+	.base.cra_module	= THIS_MODULE,
+} };
+
+static int __init crc32_pmull_mod_init(void)
+{
+	if (elf_hwcap & HWCAP_CRC32) {
+		fallback_crc32 = crc32_armv8_le;
+		fallback_crc32c = crc32c_armv8_le;
+	} else {
+		fallback_crc32 = crc32_le;
+		fallback_crc32c = __crc32c_le;
+	}
+
+	return crypto_register_shashes(crc32_pmull_algs,
+				       ARRAY_SIZE(crc32_pmull_algs));
+}
+
+static void __exit crc32_pmull_mod_exit(void)
+{
+	crypto_unregister_shashes(crc32_pmull_algs,
+				  ARRAY_SIZE(crc32_pmull_algs));
+}
+
+module_cpu_feature_match(PMULL, crc32_pmull_mod_init);
+module_exit(crc32_pmull_mod_exit);
+
+MODULE_AUTHOR("Ard Biesheuvel <ard.biesheuvel@linaro.org>");
+MODULE_LICENSE("GPL v2");